Sanada Masayuki was a Japanese Sengoku period lord and daimyō. He was the head of Sanada clan, a regional house of Shinano Province, which became a vassal of the Takeda clan of Kai Province. Along with his father and brothers, Masayuki served the Takeda clan during its heyday, when it was led by Takeda Shingen. After its downfall, Masayuki took the lead of his clan and, despite little power, he managed to establish himself as an independent daimyō under the Toyotomi regime through skillful political maneuvers amidst the powerful Tokugawa, Hojō and Uesugi clans.

Takeda Shingen was daimyo of Kai Province during the Sengoku period of Japan. Known as the "Tiger of Kai", he was one of the most powerful daimyo of the late Sengoku period, and credited with exceptional military prestige. Shingen was based in a poor area with little arable land and no access to the sea, but he became one of Japan's leading daimyo. His skills are highly esteemed and on par with Mōri Motonari.